Initial Results from Summit: An Ongoing, 3-Part, Multi-Center, Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Study of Bezuclastinib in Adult Patients with Nonadvanced Systemic Mastocytosis (NonAdvSM)

作者：P. Bose, Stephen T Oh, Brian D. Modena, Anthony M. Hunter, Cem Akin, M. Castells, Michael Manning, Richard Herrscher, F. Siebenhaar, D. DeAngelo, T. George, B. Exter, Jenna Zhang, A. Pilla, H. Jolin, R. Easton, L. Rein · 发表于：Blood · 年份：2023 · DOI：10.1182/blood-2023-178927 · 被引用次数：6

Background: Systemic mastocytosis (SM) is a rare disease characterized by neoplastic mast cell infiltration of extracutaneous tissues and encompasses a spectrum of subtypes that can range from non-advanced to advanced disease. Nonadvanced SM (NonAdvSM) includes two variants of SM: indolent systemic mastocytosis (ISM) and smoldering systemic mastocytosis (SSM). NonAdvSM is often associated with debilitating symptoms which may significantly reduce health-related quality of life (HRQoL). In up to 95% of patients, SM is driven by the somatic KIT D816V gain of function mutation located in exon 17. Bezuclastinib (CGT9486) is an oral, potent, and selective type 1 tyrosine kinase inhibitor (TKI) with activity against KIT D816V. Preclinical studies demonstrate bezuclastinib inhibits KIT D816V with minimal brain penetration. Early results from Part 1 of a Phase 2 trial of patients with AdvSM demonstrate that bezuclastinib is well-tolerated and is associated with encouraging clinical activity. Bezuclastinib resulted in meaningful reductions in markers of disease burden including serum tryptase, bone marrow mast cell burden, and KIT D816V variant allele fraction (DeAngelo et al. [abstract] In: Blood (ASH) 2022; 140 (Supplement 1): 1512-13). These results support the investigation of bezuclastinib as a potential therapy in NonAdvSM. Study Design and Methods: Summit (NCT05186753) is a multi-center, Phase 2, randomized, double-blind, placebo-controlled, 3-part clinical trial of bezuclasti...